Mr Campbell accidently telephoned his own girlfriend while the pair were together, the court heard.

She recognised their voices and posted a message about the incident on her Facebook page.

Lyn found out he had been cheated on while checking his phone on the bus ride home from his agency job in the complaints department at the Morrisons head office, Bradford.

Mr Moulson said Lyn visited the Aldi supermarket at Lane Gardens, Elland, and purchased a packet of three knives from the store.

He drank half a bottle of brandy and hid two of the knives and the packet they came in in a toilet cubicle at the Travellers
Rest public house on Huddersfield Road, Elland.

The court heard Lyn then headed to Mr Campbell’s home at around 7.20pm with a six-inch chef’s knife - a neighbour who saw him said Lyn “looked possessed.”

Lyn knocked on a neighbour’s door and asked if they knew where Mr Campbell was, he said: “I’ve got a surprise for Danny.”

Mr Moulson told the court that Lyn started kicking Mr Campbell’s front door, and could be heard shouting “I know you’re in there - let me show you what a real man looks like.”

Lyn then picked up a concrete plant pot and used it to force open the front door.

Lyn found Mr Campbell sleeping in his bed, he then stabbed Mr Campbell 20 times in the neck and abdomen.

The court heard that while this was happening, Lyn’s girlfriend was in the bathroom unaware of what had happened to Mr Campbell.

She emerged from the bathroom and was confronted by a bloody Lyn who said: “How do you like your boyfriend now?”

Lyn left the scene and made his way to a nearby take-away and asked the owners to call him a taxi.

The court heard that when the taxi arrived, Lyn lay on the back seat covered in blood and told the driver to “go go go.”

The driver said he was going to call the police and Lyn ran from the cab and headed towards Elland town centre.

Lyn was quickly chased down and arrested by PC Gallagher who gave chase and an off-duty officer PC Macnamara who happened to be passing in his car.

Upon arrest Lyn asked the officers “Is he dead yet?” and said “What would you do if you found out your girlfriend had been cheating?”

The judge applauded both officers for their bravery and quick thinking, adding that they had potentially saved a lot of police resources by bringing Lyn into custody so quickly.

A statement from Mr Campbell’s mother read out the court described her grief at the sudden loss of her son.

She said: He was a pleasure to be with and had a lot to live for.

“I have a Daniel shaped void in my life that will be with me forever.”

Richard Wright QC, defense counsel for Lyn, told the court: “This was a pointless and needless death” and said Lyn was “wholly remorseful” for what had happened.

Summarising the case, Judge Coulson said: “However upset you may have been, you do not inflict violence, especially this level of violence, before you speak to the man.

“I do not accept that you were provoked - you are 45 not 15.”

Judge Coulson considered the “appalling injuries on a sleeping and defenceless man.”
He told Lyn: “You butchered him.”

The judge outlined Lyn’s previous convictions which included robbery, assaulting a police officer and possessing a knife in a public place.

Lyn, of Huntingdon Avenue, Huddersfield, will serve a minimum of 26 years in prison.

After the case, Det Ch Insp Steve Snow, of Protective Services (Crime), said: “Daniel was a quiet, caring and loving son, who was loved by all his family. However, on July 18 the lives of Daniel Campbell’s family were changed forever by Robert Lyn.

“Lyn’s brutal attack was fuelled solely by jealousy and he subjected Daniel to a violent, sustained and savage attack whilst he lay in his bed, for which he has shown no remorse.

“The events of that evening have without doubt had a significant and profound effect on Daniel’s family.

“Robert Lyn is a dangerous individual who, today, has been sentenced to spend his life in prison for this brutal attack.

“I hope that today’s sentence can bring some small comfort to the family of Daniel, who hopefully one day can start to rebuild their lives.”